Opening your eyes momentarily and then closing them is fine. The WILD community refers to that as Reverse Blinking, which can actually help with WILDs at times. I've experienced that sudden jolt wakefulness before, no idea what its from haha. That spazzing though, was it like a vibrating feeling? If it was you might have been experiencing some Out of Body Experience symptoms. I think Dolphin has it down about the hypnotic jerk though.